Process for treating metallic slimes.



NT einen.

JAMEsDnNs'roNE. ora-DOLLAR BAY, liaonrefaiv. p

PnooEss For.V renaming METALLIdsLIMEs.

pecat'rqf itters E11-teilt..A l v 'Patented May 3v, 1910.

Application ledNlvember 2V, 1908. Serial No, 469,715.

To all whom it 'may concern:

Beit known that I, Jamas Durzsronn, a citizen of the United States, residing at Dollar'Bay, inthe county of Houghton, State of Michigan, have invented certain new and useful Improvements in Processes 'for Treating Metallic Slimes; and I do hereployed in crushing ore containing native metals.

YVhile the process has equal application to other ores it will be herein described asspecitcally applied to copper ore for the purpose of illustrating the method of ap- \plication.

In the treatment of such ores as those found in the copper mines of the Lake Superior district, the ores are worked to recover nativeco per. Thiscopper is embedded in what 1s called vein rock, the copper granules varying in size from pieces as large as chestnuts to microscopic particles.

' problem of separation becomes morediffi-v The latter grade is so fine that the ordinary methods of separation are ineffective, it resembling flour to the touch.

In working the ore the vein rock is sent from the mine to a stamp mill in pieces of varying sizes. At the stamp mill,the rock iscrushed to free the metallic. copper from its matrix.` specific gravity than the sand resulting from the crushing is easily separated by theusual 'hydraulic method so long as the particles are ofsuflicien't size to readily sink through water. IVith the finest grains or slimes, the

cult. The rougher or larger grains can-be sent directly vfrom the stamp mills to 'the' smelter and the concentrate thus sent contains from seventy-live to ninety per cent. of metallic copper. The slime-concentrate, however, contains only about fifteen per cent. copper so that in order torecover three hundred pounds of copper from' the-,slimes two thousand pounds of slime has to be smelted, making it necessary yto smelt seven--l teen hundred pounds of slime sand in addition -to the metallic copper. This process is naturally very ,expensive Hi'therto,` -attempts to concentrate the slimes so that more subjected tov the following treatment.

be treated.

The copper being of a greater.

thanifteen per cent. of metallic copper will be contained therein have resultedy infailure owing tothe fact that 'some of the copper was` lost in the attempt. Even when` metal so that all of the met-al will be separated from the slime.

In the accompanying drawing reference characters are used to indicate the several parts, and the figure represents a 'Vertical' section through a form of apparatus yadapted for use with this process. 4 l 1".;

lVith this object 'in view, the slimes are A charge of slime concentrate is placed in. a

suitable vessel 10 provided with a metallicl lining l1, `It is then covered with 'water to a suitable depth, this being determined .by the grade of ore and n ature of the metal to To this there is added one pound of sulfuric acid to about one hundred andtwenty pounds of the charge of slime. This|"mixture is then violently agitated by any "suitable `means such as a plunger 12 until a thin sheet'of 'copper appears on the surface of the water. lWhen this occurs a light mineral oil such askerosene is added to the extent of four times as much in bulk as the charge of slime. rThe entire charge is now agitated until an emulsion is formed and .when this takes place the 'globules of oil take up the particles of metal andthe process continues, the emulsion forming on the top ofI the entire charge assumes the ap- .concentrating the metallic slimes resulting f 'from the crushing of ores containing nat-ive l pearance of a copper froth. More water is now added to vthe hextent of about three fourths 'as much water as the charge of oil and the agitation continued until-a tempof rary oil `and-water emulsion is `formed. The

emulsion thus formed is now drained offat a point just above the-point occupied by the There itis allowedto rest ployuient of different styles of apparatus,

will invariably be the same, all of the metal being separated from the slimes and passing ott1 with the emulsion.

Experimentally this may be accomplished in the following manner Place about onehalf a pound of slime concentrate in a large clear-,glass bottle. Put in enough water to cover and about one-half inch over. Add to this one-teaspoonful of sulfuric acid. Shake well until a thin sheet of copper forms on the surface of the water. Now add common kerosene about four times as much in bulk as the sand or slime concentrate.`

Continue the shaking process until particles of copper will be noticed coming together and there seems to be a copper scum formed on top of the mixture. At this point add about three-fourths as much water as there is oil in the bottle, and give the bottle a few violent perpendicular shakes. This will complete the separation, a temporary oil and water emulsion being formed and in this will be seen a multitude of tiny globules of oil which resemble globules of copper owing to the fact that the copper has been taken up and adheres to the oil. At a little distance the mixture will seem to hold in suspensiona shining mass of copper about two inches highand two and one-half inches in diameter. The liquid is then drained ed into a suitable Vessel and allowed to rest. rl`he en'iulsion is destroyed during the period of rest and the copper sinks to the bottom of vthe vessel. By draining olf the iquid the slime sand remains in the bottom of the original bottle as a black and sticky mass. This result can be obtainedon a larger scale hy agitating hy means of a loose plunger which is provided with a plurality of perforations and given an up and down motion by any' suitable mechanism.

season Whether the operation be performed on the small scale just described or onl the larger scale previously described, the result is the same and all of the metal is separated from the slimes. The metal thus separated may then be sent to the smelterpfor treatment in the usual manner.

It is to be noted that the oil may be used frequently by being drawn olf the water after it has separated therefrom during the period of rest.

There has thus been provided a cheap and eiilcient process of the character described:

kerosene oil, an aqueous solution of sodium nitrate.r and an acid adapted to decompose the sodium nitrate, and collectingthe por tion floated.

3. The process consisting in agitating copper slimes in the presence of an emulsion of kerosene oil, an aqueous solution of sodium nitrate, and sulfuric acid, and collecting the portion floated.

n testimony whereof, I aliix my signature, in presence of two witnesses.

A. JAMES' DUNSTUN E. lvitnesses:

.latins MILLER,

ilnnsr VARMINsipN. 

